Da hun endelig undskyldte, blev jeg mindre skuffet og meget mere lettet.

Here da means when, referring to a specific event in the past.

A very common contrast is:

• da = when for a single completed event in the past
• når = when for something habitual, general, or future

So:

• Da hun endelig undskyldte... = when she finally apologized
• Når hun undskylder... = when she apologizes / whenever she apologizes / when she does apologize

Because da hun endelig undskyldte is a subordinate clause.

In Danish subordinate clauses, adverbs such as endelig, ikke, aldrig, and similar words often come before the finite verb. So the order is:

• da
  • subject + adverb + verb
• da hun endelig undskyldte

That is normal Danish clause structure.

Yes. Undskyldte is the simple past (preterite) of undskylde.

A few useful points:

• infinitive: at undskylde
• present: undskylder
• past: undskyldte

Danish verbs do not change according to person, so the same past-tense form is used with jeg, du, hun, vi, and so on.

Not always. Undskylde can mean either:

• to apologize
• to excuse

In this sentence, it clearly means to apologize.

That matters because English learners often know undskyld as sorry / excuse me, so it is useful to remember that the verb can cover both ideas depending on context.

This is because of the Danish V2 rule in main clauses.

The first part of the sentence, Da hun endelig undskyldte, takes the first position. After that, the finite verb of the main clause must come second, so you get:

• Da hun endelig undskyldte, blev jeg...

If you put the main clause first, then you would say:

• Jeg blev mindre skuffet og meget mere lettet, da hun endelig undskyldte.

So both are possible, but the word order changes depending on what comes first.

Because blev shows a change of state.

• blev = became / got
• var = was

So the sentence is saying that after the apology, the speaker’s feelings changed: they became less disappointed and much more relieved.

If you used var, it would describe a state, but it would not highlight the change as clearly.

Because the subject is singular: jeg.

After verbs like være and blive, these words function as predicate adjectives, and in the singular they usually appear in the basic form:

• jeg blev skuffet
• jeg blev lettet

With a plural subject, you would normally use -e:

• vi blev skuffede
• vi blev lettede

They are forms that come from past participles, but here they are functioning as adjectives.

So in this sentence:

• skuffet = disappointed
• lettet = relieved

This is very common in Danish, especially after blive and være:

• jeg blev overrasket
• hun var træt
• vi blev lettede

English does the same kind of thing in sentences like I became disappointed or I felt relieved.

Because Danish usually compares participial adjectives like skuffet and lettet with mere and mindre, not with -ere endings.

So:

• mindre skuffet = less disappointed
• mere lettet = more relieved

And:

• meget mere lettet = much more relieved

A useful extra note: lettere does exist in Danish, but it belongs to let meaning light / easy, not to lettet meaning relieved.

Endelig means finally / at last.

It suggests that the apology took a while to come, or that the speaker had been waiting for it. So it adds emotional nuance: there was delay, tension, or frustration before the apology happened.

Without endelig, the sentence would sound more neutral.

Because the comparison is understood without saying what it is compared to.

The idea is:

• less disappointed than before
• more relieved than before

Danish does not need end here because the comparison is implicit.

If you wanted to make it explicit, you could say something like:

• mindre skuffet end før
• mere lettet end jeg havde været tidligere

Because the opening da-clause is a subordinate clause placed before the main clause.

The comma marks the boundary between:

• Da hun endelig undskyldte
• blev jeg mindre skuffet og meget mere lettet

So the comma helps show where the first clause ends and the main clause begins.